The present invention generally relates to controller valves that are used to regulate the water temperature within a water heater and more particularly pertains to the mechanism by which such controller valve is attached to a water heater.
Controller valves are fitted to water heaters to perform a number of functions. In addition to sensing the water temperature within the water heater, the controller allows a set temperature to be selected, controls the flow of gas to the burner so as to maintain the water temperature at or near the set temperature and facilitates the ignition of the burner whether by pilot flame, or by electric or electronic means. Additionally, the device monitors the existence of a burner flame or pilot flame with the use of a thermocouple and/or thermopile for the purpose of shutting down the flow of gas in the event the gas fails to ignite or in the event an established flame becomes extinguished. Such controller device is typically situated on the exterior of the water heater so as to be readily accessible to allow a set temperature to be selected and in the event a pilot flame ignition system is employed, to allow manual valves to be operated during the start-up procedure. Additionally, the device includes a temperature sensor, usually in the form of an Invar rod/copper sleeve combination that extends into the interior of the water heater to sense water temperature directly. A conduit that supplies gas to the burner extends from the controller to the burner and in the event a pilot flame is relied upon for ignition, a second gas carrying conduit extends from the controller to supply gas to such pilot flame. Additionally, one or more electrical conductors may extend from the controller including interconnections to thermoccouples and/or thermopiles and to electric or electronic ignitors if present.
Gas controllers have typically been attached to water heaters via a threaded interconnection between the controller and a fitting that is welded or otherwise permanently attached to the wall of the water tank and through which the Invar rod type sensor is extended into the interior of the water tank. A number of problems are inherent in such configuration including for example the need to apply a substantial torque load to the controller in order to achieve a water tight interconnection with the threaded fitting. This is further complicated by the necessity to achieve a proper rotational orientation of the controller valve while simultaneously avoiding an over-tightening or under-tightening of the connection. Additionally, because any rigid or semi-rigid conduits that extend from the controller would physically interfere with the structure of the water heater during the threading of the controller into place if such conduits were to be attached to the controller prior to its attachment to the water heater, the preassembly of such components to the controller is precluded. This in turn precludes the testing of such assembly prior to installation on the water heater. A leak or other malfunction that is discovered after the attachment of the controller to the water heater and the attachment of all the various conduits and wires thereto requires a labor intensive effort to disassemble, repair and reassemble the entire system on and in the water heater. A need to remove the controller for repair requires reapplying potentially damaging torque loads to the controller in order to remove it from the threaded fitting and again for refitment after its repair.
It has previously been recognized that the ability to attach such controller to a water heater without the need to rotate the device into place overcomes a number of shortcomings inherent in the previously used configurations that rely on a threaded interconnection. Mechanisms have been devised which merely require longitudinally pushing the controller into a fitting positioned on the side of the water heater. In such configurations, the Invar rod-type sensor extends through the fitting into the interior of the water heater while a shank element surrounding the base of the sensor is received in an appropriately configured spud. The spud in turn is received in the internally threaded fitting that is conventionally and permanently mounted in the wall of the water tank. One or more O-rings positioned within grooves formed on the interior wall of the spud are relied upon to form a water tight seal against the exterior surface of the shank upon its insertion there into. Full insertion serves to align a groove formed about the interior surface of the spud and a groove formed about the exterior surface of the shank. An flexible retainer clip positioned within the groove formed on the shank is then free to expand into the groove formed in the spud to thereby positively lock the two components to one another. By obviating the need to rotate the controller into place, the controller along with all conduits extending therefrom can be preassembled and pretested. Any repairs or remediation efforts that may be deemed necessary as a result of the pretesting can be performed before the assembly is installed on and in the water heater, thus providing substantially more accessibility and freedom of movement to effect the repair. Additionally, such configuration obviates the need to exert any torque on the controller while allowing the controller to assume a proper rotational orientation. A number of such devices have previously been described as for example in U.S. Pat. Nos. 5,419,356 and 5,620,016.
The described mounting mechanisms do however suffer from a number of shortcomings. One such shortcoming is the fact that once the shank has been fully inserted into the spud and the retainer spring clip has expanded to lock the two components together, the components cannot be separated without destruction of the spud. The inaccessibility of the internally disposed spring clip precludes manipulation thereof in effort to release the shank from the spud while unthreading of the spud from the fitting leaves the spud in a distorted and unreuseable state. Reuse of the controller requires the complete destruction of the spud in order to free it from the retainer clip. Moreover, in order to initially remove the controller from the water heater, all of the conduits and connections to the controller must be disconnected in order to allow the spud, along with the attached controller, to be unthreaded from the fitting that is attached to the side of the water heater. This requires a substantial torque to be exerted on the controller, especially if the spud has been in place for an extended period of time, which may cause the controller to become irreparably damaged. If the controller is to be reused, the fairly labor intensive effort to remove the old spud must first be expended, after which a new spud must be threaded onto the fitting on the side of the water heater. The spud must be brought into a precise rotational orientation in order to ensure that the controller that is to be fitted thereto is properly aligned with the various conduits from which it had been previously detached. Additionally, it has been found that the O-rings that are disposed within the grooves formed on the interior of the spud are prone to being displaced upon insertion of the shank which may result in their being damaged which could in turn prevent an effective seal from being achieved. Replacement of the O-rings requires removal of the controller and destruction of the spud as described above.
An improved controller valve attachment mechanism is therefore needed that allows the controller to be attached to the water heater by simple longitudinal receipt within a spud attached to the water heater, that forms the requisite water tight seal with the water heater yet allows the controller to be removed without disassembly of the conduits extending therefrom. Additionally it is desirable that such controller should be refittable without the sacrifice of any of the components. Finally, a configuration is needed wherein O-rings are less susceptible to damage.
The present invention overcomes the shortcomings of previously known controller valve attachment mechanisms. The invention allows a controller valve to be attached to a water heater by simply pushing a shank extending from the controller onto a spud that is threadedly attached to the wall of the water heater. The shank can then be reversibly locked into place with the use of an externally applied retainer spring clip while the O-rings relied upon to effect a seal are substantially protected from damage during assembly. The configuration allows the controller and the various conduits extending therefrom to be preassembled and pretested prior to installation on a water heater. Moreover, should it become necessary to subsequently remove the controller for repair or replacement, such task is easily accomplished with minimal effort and no destruction of any parts.
The attachment mechanism of the present invention includes a shank that extends from the back of the controller and surrounds the base of Invar rod-type temperature sensor. The shank includes a groove formed on the exterior surface of proximal section near its base. Such proximal section has a diameter slightly greater than its distal section. Two grooves formed on the distal section of reduced diameter carry two O-rings which are dimensioned so as to be under slight tension. A spud is threaded onto the fitting that is in turn permanently attached to the wall of the water heater. A pair of diametrically opposed slots are formed in the spud that extend completely through its wall thickness. Such slots are positioned so as to be in alignment with a groove formed about the proximal section of the shank to allow the insertion of a retainer spring clip which serves to lock the shank and spud to one another. Removal of the spring, which is readily accessible, allows the shank to be retracted from the spud.
In one embodiment, the shank, and hence the controller, is freely rotatable with respect to the spud. In another embodiment, cooperating surfaces on the spud and shank serve to rotationally lock the two components together.
These and other features and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment which, taken in conjunction with the accompanying drawings, illustrates by way of example the principles of the invention.